Leucine Rich Repeat Neuronal Protein 4 (LRRN4)

LRRN4 may play an important role in hippocampus-dependent long-lasting memory. Neuronal leucine-rich repeat proteins (NLRRs) are type I transmembrane proteins and expressed in neuronal tissues, but their function remains unknown.

NLRR4 showed impaired memory retention. In hippocampus-dependent learning tasks, NLRR4 mice were able to learn and maintain the memories for one day but unable to retain the memories for four days after learning. In contrast, in a hippocampus-independent task, NLRR4 mice were able to retain the memory normally for at least seven days. These results suggest that NLRR4 plays a key role in hippocampus-dependent long-lasting memory. LRRN4 is similar in sequence with leucine-rich (LR) repeats and calponin homology (CH) domain containing 4 (LRCH4).